What is the largest body of fresh water in Britain?

The largest body of fresh water in Britain by surface area is Loch Lomond. This large Scottish loch stretches through the Loch Lomond and The Trossachs area and covers about 71 square kilometres, or 27.5 square miles.

Loch Lomond is a glacially shaped freshwater lake whose northern and southern sections differ noticeably in depth and character. It is about 36 kilometres long and reaches a maximum depth of roughly 190 metres. More than 20 islands sit within the loch, including Inchmurrin, commonly described as the largest island in a freshwater body in the British Isles.

The wording matters because “largest” can refer to different measurements. Loch Ness contains more water by volume, while Lough Neagh in Northern Ireland is larger by surface area if the whole United Kingdom is meant. In the usual geography convention of Great Britain—England, Scotland, and Wales—Loch Lomond is the accepted answer for largest freshwater lake by area.